Help with Air Tanks and leaks

[96 EVO]

They probably all work well.

Think it is Permatex is what I have. After screwing the fittings in, I would give the sealant about 24hrs to dry before airing up the system.

[jacwjames]

I found a supplier of the fittings in Knoxville, the prices seemed reasonable so I took a list of what I thought I needed down there and got those fittings plus spares and several of the repair coupling sizes that I didn't have.  I will also keep the old fittings as spares.    I also got some lengths of spare pieces of hosing to carry.  After really seeing how susceptible some of the hosing is to road debris I think it would be a good idea to be able to do a quick repair on the side of the road then be stranded. 

I got 3 of the 4 PPV installed.  I am going to replace the large check valve on the rear tank which also serves as a PPV, it has a diaphragm in it so could have a similar life expectancy as the smaller ones although it doesn't vent to air.   I also ordered the 150 psi relief valve and replace. 

In the mean time I have a couple of other small jobs to tackle.  No rest for the weary. 

 

[jacwjames]

I have a similar post on the IRV2 Forum page and one of the senior posters questioned the positioning of the PPV with the spring on top.  The drawings that I have all showed the PPV position that way and all of mine were positioned that way so I thought that was the way they were suppose to go.  Another senior poster indicated that the information he had did not specify orientation. 

This peaked my interest so I spent some time searching and found a Halidex installation guide that specifically states that the spring cap should be oriented down.  https://www.haldex.com/globalassets/north-america/documents/suspension-controls/l31258.pdf

So I need to go back and redo mine, better now then later. 

But I wonder how many coaches have these installed wrong.   Might pay for everyone to check!!!!!!!!!!!!

[Guest Ray Davis]

Jim, that's interesting, I wondered the same thing when I replaced mine.

Another thing on that page is it says to not use any pipe compound or tape but to use Locktite,  seemed strange to me.    I knew the risk of using thread tape, but Locktite !!!

Here is a copy of that statement.

"Use a drop of Loctite to lubricate threaded connections. DO NOT USE a pipe compound or teflon tape as they may clog the valve." 

I bet this is what they want us to use.

 

[jacwjames]

The fittings that I got all had a preapplied sealant but I bought a couple tubes of Permatex Thread Sealer to use. 

I have to redo the position of mine, hope I and turn each the 1/2 turn, I got them pretty tight now.  One will have to have the 90 degree fitting turned aslo.   But I'd rather do it right this time then have to do it again later. 

Wonder if the positioning contributed to failure. 

[jacwjames]

Luckily I was able to reposition the PPV's without too much problem.  Only had to take one hose loose, the rest were on swivel type fittings that would spin.

I decided to replace all the mechanical type fittings, check valves, pressure relief valves etc.  The check valves have a rubber type diaphragm that could fails so thought it better to be safe then sorry. 

I ended up breaking off the pressure relief valve and had to saw the piece in the bung hole and using a punch to remove.  Brass on steel doesnt' lay well, I sprayed PB blaster on it yesterday but it didn't help.  But I got it out and all the parts are on order. 

One good thing about this whole exercise is that it has forced me to look at the air schematics I had and understand the system.   Ultimately this will hep me in case of emergency.  After looking at the drawings and working on both the front and rear tanks I understand how it works and why they did what they did.    My challenge now will be to retain all the info in my brain, which seems to be not as receptive as in the past to storing the information.🤬

Edited December 4, 2021 by jacwjames

[amphi_sc]

Jim, I've been following this with great interest and don't mean to hijack.  But have a fairly related question.  I have the Valid Power Gear air leveling.  Somewhat recently (last couple months) the air compressor comes on for 26 seconds every 45 minutes after the first night.  My main tanks have always bled down over night but the air suspension might have come on a couple times a day after I heard it bleed air or add air when the brain said it was slightly off level ... usually due to temperature changes... even when parked for 3 weeks.  With the digital dash air guage display I see both front and rear tanks losing pretty equally about 6-7 lbs an hour down to 45 lbs and then I lost track as it goes to zero eventually.  If I auto level and then switch to manual the coach will stay level for days holding air in the bags, so I pull the FRB air compressor circuit breaker out so the pump stays off. I've sprayed the lines from pump thru pressure switch and check valve to the first tank and no bubbles.  Yes, there are tiny bubbles by the tag axle adjust knob as well as a little by the dash parking brake so I can see why the brake tanks bleed down some.  If the electric aux compressor is allowed to run it doesn't pump up either front nor rear tank as indicated by the digital gauge but quickly fills the tank it is plumbed into.  The main engine driven pump fills the system fine and cycles as it should ... losing a couple of pounds in 15 minutes as I drive down the freeway.

Where should I look for the reason the pump comes on regularly AFTER the first day of parking?  It pumps back up fast (26 seconds) but repeats in less than an hour on either auto or manual mode.

Al

Edited December 5, 2021 by amphi_sc

[jacwjames]

7 hours ago, amphi_sc said:

Jim, I've been following this with great interest and don't mean to hijack.  But have a fairly related question.  I have the Valid Power Gear air leveling.  Somewhat recently (last couple months) the air compressor comes on for 26 seconds every 45 minutes after the first night.  My main tanks have always bled down over night but the air suspension might have come on a couple times a day after I heard it bleed air or add air when the brain said it was slightly off level ... usually due to temperature changes... even when parked for 3 weeks.  With the digital dash air guage display I see both front and rear tanks losing pretty equally about 6-7 lbs an hour down to 45 lbs and then I lost track as it goes to zero eventually.  If I auto level and then switch to manual the coach will stay level for days holding air in the bags, so I pull the FRB air compressor circuit breaker out so the pump stays off. I've sprayed the lines from pump thru pressure switch and check valve to the first tank and no bubbles.  Yes, there are tiny bubbles by the tag axle adjust knob as well as a little by the dash parking brake so I can see why the brake tanks bleed down some.  If the electric aux compressor is allowed to run it doesn't pump up either front nor rear tank as indicated by the digital gauge but quickly fills the tank it is plumbed into.  The main engine driven pump fills the system fine and cycles as it should ... losing a couple of pounds in 15 minutes as I drive down the freeway.

Where should I look for the reason the pump comes on regularly AFTER the first day of parking?  It pumps back up fast (26 seconds) but repeats in less than an hour on either auto or manual mode.

Al

I do not have air leveling, I have jacks, so not sure where you should look.  In reading other posts I keep seeing the 6-pack valve referenced which is what I believe controls the leveling function. 

You might be better off starting your own thread as not to muddle this one with unrelated information. 

[isptbart]

ALL - 

Re: Tag Axle Issue - UPDATE! 12/03/2021
From: Bart from VA
Date: Sat, 04 Dec 2021 21:06:11 EST

ALL - I was finally able to get my RV in the shop & after some serious searching - they replaced a Preventative Pressure Valve (PPV), Wabco #4341003100, my Meritor Wabco Air Dryer Filter R950011 or NAPA Gold Filter #4374, & most importantly one of my Tag Axle air canister diaphragms WRP Type 30. The diaphragm was the" main source" of the problem because over time it had blown out an edge of the seal, resulting in enough of a leak that the tag axle could not operate. My air canisters are located in an extremely difficult & unusual location but raising the coach, removing a tag wheel & with the tech working on his knees & stretching up at arms length made it possible. The tag now raises properly, but I still have other leak(s) which causes the rear tank to almost totally drain overnight. It is a small but steady leak which takes hours but I still want to try to track them down! The tech pointed out neither of my two air tanks have a way to drain the tanks w/o actually removing drain plugs & suggested I could add one of the various spring-loaded air tank drain valves to make things easy. I'm looking for the best style for my potential use. Does anyone else have such a valve installed on their air tanks?

[96 EVO]

5 hours ago, isptbart said:

ALL - 

Re: Tag Axle Issue - UPDATE! 12/03/2021
From: Bart from VA
Date: Sat, 04 Dec 2021 21:06:11 EST

  The tech pointed out neither of my two air tanks have a way to drain the tanks w/o actually removing drain plugs & suggested I could add one of the various spring-loaded air tank drain valves to make things easy. I'm looking for the best style for my potential use. Does anyone else have such a valve installed on their air tanks?

Probably should have started a new thread with this issue.

My 08' model has all 3 tank drain valves mounted in an air manifold in the generator compartment. If your tech was looking for traditional lanyard style drain valves, he's not going to find them 'if your 07' model is the same as my 08'.

[Jimmer]

On 12/2/2021 at 6:04 AM, miacasa_2000 said:

Food for thought.   When I replaced all of mine I also replaced all the fittings with DOT approved swivel fittings. Reason being if I needed to replace the ppv again I would not have to take any airlines out of the fittings again and avoid all that goes along with that. I was a little concerned about leaks at the swivel so I checked them often and no leaks. 

Roy  2003 dynasty

 

[Jimmer]

Just now, Jimmer said:

 

I have had some leaks on new push on style around the lock and unlock ring. I am using more compression style now.

After eliminating 2 leaks at the front tank position my air leak is now greater. 15lbs in one hour. very frustrating. I have sprayed soapy water on all connections I can find, no leaks.  I notice that those Advance auto PPVs have no designation on them like DOT. Nothing says where they are made. My local truck repair shop sells DOT for $45@. I have replaced  the 2 front tank PPV and one on the rear tank. One of the 3 was leaking at the gasket.

Before I started to fix my leaks at the tanks my air pressure was at zero in four days. Now 0 in 8 hours.

[jacwjames]

Two steps forward and three steps back.

I'll look at the PPV's I got from Advanced Auto, can't recall if they have DOT on them or not.  I'll be disappointed if they aren't DOT approved!!

I haven't got far enough along with my air system to try and pressurize.  I am waiting on some more parts.  I decided to just go ahead and replace any of the tank connections that have the potential to fail, new fittings, new check valves, PPV's, etc. 

[isptbart]

Jim - I just did a complete spray down for as many fittings as I could find. The last place I checked was a bank of fittings at the rear of my coach & I found an air fitting leaker going to the tag axle pressure regulator. After replacing the air fitting & airing up the coach pressure again - after turning everything off I discovered air coming out of my Air Dryer exhaust port. It leaked out for about a minute & both tank air pressure gauges dropped from about 115# to approximately 80# & then it just stopped. I re-pressurized the tank again & did a re-check of the Air Dryer, but no more leakage so far. BTW, I also found what looks like a small air tank, about the size of a small metal coffee can, located up high above the rear axle too! I had no idea it was there! Will check pressures again in the morning!

Bart from VA

[Jimmer]

6 hours ago, jacwjames said:

Two steps forward and three steps back.

I'll look at the PPV's I got from Advanced Auto, can't recall if they have DOT on them or not.  I'll be disappointed if they aren't DOT approved!!

I haven't got far enough along with my air system to try and pressurize.  I am waiting on some more parts.  I decided to just go ahead and replace any of the tank connections that have the potential to fail, new fittings, new check valves, PPV's, etc. 

My original equipment Meritor Wabco PPV does not have a DOT stamped on it.

My red and green needles drop uniformly even though my rear tank has a leak but no leaks on the front tank. So maybe there is a common location/fitting shared by both tanks that is leaking both tanks down.  I do not hear air leaking even with my hearing aid turned to max sensitivity, but.

Maybe at the air dryer exhaust port, like Bart mentioned.

Any ideas out there where i should go next.

39 minutes ago, isptbart said:

Jim - I just did a complete spray down for as many fittings as I could find. The last place I checked was a bank of fittings at the rear of my coach & I found an air fitting leaker going to the tag axle pressure regulator. After replacing the air fitting & airing up the coach pressure again - after turning everything off I discovered air coming out of my Air Dryer exhaust port. It leaked out for about a minute & both tank air pressure gauges dropped from about 115# to approximately 80# & then it just stopped. I re-pressurized the tank again & did a re-check of the Air Dryer, but no more leakage so far. BTW, I also found what looks like a small air tank, about the size of a small metal coffee can, located up high above the rear axle too! I had no idea it was there! Will check pressures again in the morning!

Bart from VA

 

did you do something to fix the air dryer exhaust port to get it working again.

[Jdw12345]

I might have posted this before but I’ll post it again, it sounds like you may have to rebuild the purge valve, easy pezy!

 

https://www.wabco-customercentre.com/catalog/docs/mm34_web.pdf

[isptbart]

4 hours ago, Jimmer said:

My original equipment Meritor Wabco PPV does not have a DOT stamped on it.

My red and green needles drop uniformly even though my rear tank has a leak but no leaks on the front tank. So maybe there is a common location/fitting shared by both tanks that is leaking both tanks down.  I do not hear air leaking even with my hearing aid turned to max sensitivity, but.

Maybe at the air dryer exhaust port, like Bart mentioned.

Any ideas out there where i should go next.

 

did you do something to fix the air dryer exhaust port to get it working again.

I could hear the hissing leak from the air dryer exhaust port. I had previously attached a flexible hose to the outlet port which directs the air purge down closer to the ground, so easy to hear via the flexible tube. All I did was re-pressurize it back to 115# & when I turned off the key, no more hissing. Perhaps the purge dislodged something to make it seal again properly? Bart

38 minutes ago, Jdw12345 said:

I might have posted this before but I’ll post it again, it sounds like you may have to rebuild the purge valve, easy pezy!

 

https://www.wabco-customercentre.com/catalog/docs/mm34_web.pdf

Hey thanks! Bart

[Jdw12345]

Fwiw,  it’s highly unlikely that you’re air drier fixed itself!

 

 We purchased a new to us 05 Dynasty in September, first thing I did was serviced the air dryer and replaced the purge valve and desiccant, after the rebuild it was crisp when it purged, if that makes sense, after the rebuild you can hear the difference! At least I could.

Edited December 7, 2021 by Jdw12345

[Jdw12345]

Two other items to check in the system if you haven’t is the air tank remote drain valves, the one in the back of my coach leaks pretty good, and the remote air chuck for airing up the coach. 

There might be an air supply chuck somewhere on your coach also to check for leaks, mine is in the propane tank compartment.

The unfortunate part is the previous owner/owners haven’t maintained the air dryer, (ie changed the desiccant cartridge) there’s nothing you can do to reverse the effects.

   As far as the leaking after the purge, read page 3 and 4 on the link I sent you to understand what might be happening also with the air flow after the purge, it might be a drying cycle depending upon what configuration of dryer you might have.

Edited December 7, 2021 by Jdw12345

[isptbart]

Jim - good point on the purge/drying cycle!!!! I just checked this morning & my air tank pressures held steady over-night after changing out a leaking 3/8" air line fitting. Finally making progress with the air system! Thanks for your help!

Bart from VA

[isptbart]

12 hours ago, Jdw12345 said:

Fwiw,  it’s highly unlikely that you’re air drier fixed itself!

 

 We purchased a new to us 05 Dynasty in September, first thing I did was serviced the air dryer and replaced the purge valve and desiccant, after the rebuild it was crisp when it purged, if that makes sense, after the rebuild you can hear the difference! At least I could.

I don't think it fixed itself - I just said it didn't repeat the extended hissing noise after re-filling the tank. Perhaps it was the additional purge cycle that happens when the air back flows to help dry out the air dryer desiccant filter?

In any case, the tanks did hold their pressure over-night!

Thanks! 

12 hours ago, Jdw12345 said:

Fwiw,  it’s highly unlikely that you’re air drier fixed itself!

 

 We purchased a new to us 05 Dynasty in September, first thing I did was serviced the air dryer and replaced the purge valve and desiccant, after the rebuild it was crisp when it purged, if that makes sense, after the rebuild you can hear the difference! At least I could.

BTW - you replaced which purge valve from where? From the air dryer itself or a different valve somewhere?

Thanks! Bart

[Jimmer]

2 hours ago, isptbart said:

Jim - good point on the purge/drying cycle!!!! I just checked this morning & my air tank pressures held steady over-night after changing out a leaking 3/8" air line fitting. Finally making progress with the air system! Thanks for your help!

Bart from VA

What was your procedure of refitting the leaking line?

[Jdw12345]

The purge valve on the bottom of the air dryer.

Edited December 7, 2021 by Jdw12345

[vanwill52]

5 hours ago, isptbart said:

Jim - good point on the purge/drying cycle!!!! I just checked this morning & my air tank pressures held steady over-night after changing out a leaking 3/8" air line fitting. Finally making progress with the air system! Thanks for your help!

Bart from VA

Bart, from my personal experience of many, many hours trying to solve my air leakage problems on my "vintage" 2000 Dynasty, I will offer the following OPINION.

The PTC (push-to-connect) fittings have been used (are still used?) on hundreds of commercial vehicles.  If there was ever an industry-wide recall, I am not aware of it.  In the vast majority of cases in which they are INSTALLED PROPERLY, they give good service for decades.

There is, however, one easy-to-make mistake in installation--not having enough of the nylon tubing extending STRAIGHT out of the fitting.  Proper sealing of the fitting requires that the tubing exits STRAIGHT from the fitting for at least a few inches (longer is better). 

On my coach, perhaps the most unlikely leak came from my treadle valve (air brake "master cylinder").  It was not (IMO) the treadle valve itself that was leaking, but I had determined conclusively the treadle valve was the GENERAL location of a serious leak--so much so that on an extremely quiet day I could HEAR the leak.  Since even servicing the fittings to the treadle valve required an unusually small person who was also a contortionist, this was one of the few jobs I ever let my trusted heavy-truck shop do for me...and I had them replace not only ALL the treadle valve fittings, but also the treadle valve itself.  I asked the talented contortionist to look closely for one thing--ANY lines exiting the treadle valve that did not exit with PLENTY of extra "slack", such that they were not being pulled to one side of the fitting as they exited.  I provided him with multiple replacement fittings of every conceivable type, couplers, and properly colored tubing.  I told him that if he found ANY tubing which did not exit in a gentle, generous arc, to either replace the tubing or add a couple of inches and lengthen it.  Luckily, that made his job much easier.  He later reported to me that ALL the tubing connected to the treadle valve seemed to have been cut too short and was leaving the fittings at an immediate angle.

By the time I had (at last) resorted to using someone to help me with this, I had replaced all three ride-height valves, ALL PPV (pressure protection valves), the parking brake valve, and a couple of PTC fittings.  I still had a leak that would drain my tanks down to 30 PSI overnight and settle my coach on its stops in three days.  The treadle valve "fix" changed it all to the point that I can now leave the coach parked in my shed (at my house) for weeks at a time before the instrument panel gage reads less than 60 PSI.

Bart, as I look at the pix you provided, I would predict that the yellow line in the far-right of your pix will be the next to cause a leak problem.  The PTC fittings are reliable...but the lines connected to them MUST not be at an angle or in a bind.  If they are, one or more of them will INEVETIBLY be the source of a leak.

If you are truly (anally?) committed to eliminating ALL leaks (as I was), you will replace many fittings/hoses/devices that do NOT appear to be a problem.  IMHO, once your coach can maintain 60 PSI overnight, and your suspension bags have not lowered your coach to its stops, your air system is OK.  Whether you expend the dollars and hours to make it 99% versus 90% is up to you.

Bless you in either path you choose.

[isptbart]

26 minutes ago, vanwill52 said:

Bart, from my personal experience of many, many hours trying to solve my air leakage problems on my "vintage" 2000 Dynasty, I will offer the following OPINION.

The PTC (push-to-connect) fittings have been used (are still used?) on hundreds of commercial vehicles.  If there was ever an industry-wide recall, I am not aware of it.  In the vast majority of cases in which they are INSTALLED PROPERLY, they give good service for decades.

There is, however, one easy-to-make mistake in installation--not having enough of the nylon tubing extending STRAIGHT out of the fitting.  Proper sealing of the fitting requires that the tubing exits STRAIGHT from the fitting for at least a few inches (longer is better). 

On my coach, perhaps the most unlikely leak came from my treadle valve (air brake "master cylinder").  It was not (IMO) the treadle valve itself that was leaking, but I had determined conclusively the treadle valve was the GENERAL location of a serious leak--so much so that on an extremely quiet day I could HEAR the leak.  Since even servicing the fittings to the treadle valve required an unusually small person who was also a contortionist, this was one of the few jobs I ever let my trusted heavy-truck shop do for me...and I had them replace not only ALL the treadle valve fittings, but also the treadle valve itself.  I asked the talented contortionist to look closely for one thing--ANY lines exiting the treadle valve that did not exit with PLENTY of extra "slack", such that they were not being pulled to one side of the fitting as they exited.  I provided him with multiple replacement fittings of every conceivable type, couplers, and properly colored tubing.  I told him that if he found ANY tubing which did not exit in a gentle, generous arc, to either replace the tubing or add a couple of inches and lengthen it.  Luckily, that made his job much easier.  He later reported to me that ALL the tubing connected to the treadle valve seemed to have been cut too short and was leaving the fittings at an immediate angle.

By the time I had (at last) resorted to using someone to help me with this, I had replaced all three ride-height valves, ALL PPV (pressure protection valves), the parking brake valve, and a couple of PTC fittings.  I still had a leak that would drain my tanks down to 30 PSI overnight and settle my coach on its stops in three days.  The treadle valve "fix" changed it all to the point that I can now leave the coach parked in my shed (at my house) for weeks at a time before the instrument panel gage reads less than 60 PSI.

Bart, as I look at the pix you provided, I would predict that the yellow line in the far-right of your pix will be the next to cause a leak problem.  The PTC fittings are reliable...but the lines connected to them MUST not be at an angle or in a bind.  If they are, one or more of them will INEVETIBLY be the source of a leak.

If you are truly (anally?) committed to eliminating ALL leaks (as I was), you will replace many fittings/hoses/devices that do NOT appear to be a problem.  IMHO, once your coach can maintain 60 PSI overnight, and your suspension bags have not lowered your coach to its stops, your air system is OK.  Whether you expend the dollars and hours to make it 99% versus 90% is up to you.

Bless you in either path you choose.

Great advice! I tried to purchase extra fittings today but my NAPA shop was out & on back order. They also only had 3/8" air hose in black - I bought a piece anyway for a backup or for future use. Many Thanks! Bart

Bart